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<h1>examples/OpenCV/contours/contours.cpp</h1><div class="fragment"><pre class="fragment"><a name="l00001"></a>00001 <span class="comment">/*</span>
<a name="l00002"></a>00002 <span class="comment">This source is one of the sample codes from the OpenCV 2.1 library</span>
<a name="l00003"></a>00003 <span class="comment">Please see copyrights of that library for its usage.</span>
<a name="l00004"></a>00004 <span class="comment">*/</span>
<a name="l00005"></a>00005 
<a name="l00006"></a>00006 <span class="preprocessor">#ifdef _CH_</span>
<a name="l00007"></a>00007 <span class="preprocessor"></span><span class="preprocessor">#pragma package &lt;opencv&gt;</span>
<a name="l00008"></a>00008 <span class="preprocessor"></span><span class="preprocessor">#endif</span>
<a name="l00009"></a>00009 <span class="preprocessor"></span>
<a name="l00010"></a>00010 <span class="preprocessor">#define CV_NO_BACKWARD_COMPATIBILITY</span>
<a name="l00011"></a>00011 <span class="preprocessor"></span>
<a name="l00012"></a>00012 <span class="preprocessor">#ifndef _EiC</span>
<a name="l00013"></a>00013 <span class="preprocessor"></span><span class="preprocessor">#include &lt;opencv/cv.h&gt;</span>
<a name="l00014"></a>00014 <span class="preprocessor">#include &lt;opencv/highgui.h&gt;</span>
<a name="l00015"></a>00015 <span class="preprocessor">#include &lt;math.h&gt;</span>
<a name="l00016"></a>00016 <span class="preprocessor">#endif</span>
<a name="l00017"></a>00017 <span class="preprocessor"></span>
<a name="l00018"></a>00018 <span class="preprocessor">#define w 500</span>
<a name="l00019"></a>00019 <span class="preprocessor"></span><span class="keywordtype">int</span> levels = 3;
<a name="l00020"></a>00020 CvSeq* contours = 0;
<a name="l00021"></a>00021 
<a name="l00022"></a>00022 <span class="keywordtype">void</span> on_trackbar(<span class="keywordtype">int</span> pos)
<a name="l00023"></a>00023 {
<a name="l00024"></a>00024     IplImage* cnt_img = cvCreateImage( cvSize(w,w), 8, 3 );
<a name="l00025"></a>00025     CvSeq* _contours = contours;
<a name="l00026"></a>00026     <span class="keywordtype">int</span> _levels = levels - 3;
<a name="l00027"></a>00027     <span class="keywordflow">if</span>( _levels &lt;= 0 ) <span class="comment">// get to the nearest face to make it look more funny</span>
<a name="l00028"></a>00028         _contours = _contours-&gt;h_next-&gt;h_next-&gt;h_next;
<a name="l00029"></a>00029     cvZero( cnt_img );
<a name="l00030"></a>00030     cvDrawContours( cnt_img, _contours, CV_RGB(255,0,0), CV_RGB(0,255,0), _levels, 3, CV_AA, cvPoint(0,0) );
<a name="l00031"></a>00031     cvShowImage( <span class="stringliteral">&quot;contours&quot;</span>, cnt_img );
<a name="l00032"></a>00032     cvReleaseImage( &amp;cnt_img );
<a name="l00033"></a>00033 }
<a name="l00034"></a>00034 
<a name="l00035"></a>00035 <span class="keywordtype">int</span> main( <span class="keywordtype">int</span> argc, <span class="keywordtype">char</span>** argv )
<a name="l00036"></a>00036 {
<a name="l00037"></a>00037     <span class="keywordtype">int</span> i, j;
<a name="l00038"></a>00038     CvMemStorage* storage = cvCreateMemStorage(0);
<a name="l00039"></a>00039     IplImage* img = cvCreateImage( cvSize(w,w), 8, 1 );
<a name="l00040"></a>00040 
<a name="l00041"></a>00041     cvZero( img );
<a name="l00042"></a>00042 
<a name="l00043"></a>00043     <span class="keywordflow">for</span>( i=0; i &lt; 6; i++ )
<a name="l00044"></a>00044     {
<a name="l00045"></a>00045         <span class="keywordtype">int</span> dx = (i%2)*250 - 30;
<a name="l00046"></a>00046         <span class="keywordtype">int</span> dy = (i/2)*150;
<a name="l00047"></a>00047         CvScalar white = cvRealScalar(255);
<a name="l00048"></a>00048         CvScalar black = cvRealScalar(0);
<a name="l00049"></a>00049 
<a name="l00050"></a>00050         <span class="keywordflow">if</span>( i == 0 )
<a name="l00051"></a>00051         {
<a name="l00052"></a>00052             <span class="keywordflow">for</span>( j = 0; j &lt;= 10; j++ )
<a name="l00053"></a>00053             {
<a name="l00054"></a>00054                 <span class="keywordtype">double</span> angle = (j+5)*CV_PI/21;
<a name="l00055"></a>00055                 cvLine(img, cvPoint(cvRound(dx+100+j*10-80*cos(angle)),
<a name="l00056"></a>00056                     cvRound(dy+100-90*sin(angle))),
<a name="l00057"></a>00057                     cvPoint(cvRound(dx+100+j*10-30*cos(angle)),
<a name="l00058"></a>00058                     cvRound(dy+100-30*sin(angle))), white, 1, 8, 0);
<a name="l00059"></a>00059             }
<a name="l00060"></a>00060         }
<a name="l00061"></a>00061 
<a name="l00062"></a>00062         cvEllipse( img, cvPoint(dx+150, dy+100), cvSize(100,70), 0, 0, 360, white, -1, 8, 0 );
<a name="l00063"></a>00063         cvEllipse( img, cvPoint(dx+115, dy+70), cvSize(30,20), 0, 0, 360, black, -1, 8, 0 );
<a name="l00064"></a>00064         cvEllipse( img, cvPoint(dx+185, dy+70), cvSize(30,20), 0, 0, 360, black, -1, 8, 0 );
<a name="l00065"></a>00065         cvEllipse( img, cvPoint(dx+115, dy+70), cvSize(15,15), 0, 0, 360, white, -1, 8, 0 );
<a name="l00066"></a>00066         cvEllipse( img, cvPoint(dx+185, dy+70), cvSize(15,15), 0, 0, 360, white, -1, 8, 0 );
<a name="l00067"></a>00067         cvEllipse( img, cvPoint(dx+115, dy+70), cvSize(5,5), 0, 0, 360, black, -1, 8, 0 );
<a name="l00068"></a>00068         cvEllipse( img, cvPoint(dx+185, dy+70), cvSize(5,5), 0, 0, 360, black, -1, 8, 0 );
<a name="l00069"></a>00069         cvEllipse( img, cvPoint(dx+150, dy+100), cvSize(10,5), 0, 0, 360, black, -1, 8, 0 );
<a name="l00070"></a>00070         cvEllipse( img, cvPoint(dx+150, dy+150), cvSize(40,10), 0, 0, 360, black, -1, 8, 0 );
<a name="l00071"></a>00071         cvEllipse( img, cvPoint(dx+27, dy+100), cvSize(20,35), 0, 0, 360, white, -1, 8, 0 );
<a name="l00072"></a>00072         cvEllipse( img, cvPoint(dx+273, dy+100), cvSize(20,35), 0, 0, 360, white, -1, 8, 0 );
<a name="l00073"></a>00073     }
<a name="l00074"></a>00074 
<a name="l00075"></a>00075     cvNamedWindow( <span class="stringliteral">&quot;image&quot;</span>, 1 );
<a name="l00076"></a>00076     cvShowImage( <span class="stringliteral">&quot;image&quot;</span>, img );
<a name="l00077"></a>00077 
<a name="l00078"></a>00078     cvFindContours( img, storage, &amp;contours, <span class="keyword">sizeof</span>(CvContour),
<a name="l00079"></a>00079                     CV_RETR_TREE, CV_CHAIN_APPROX_SIMPLE, cvPoint(0,0) );
<a name="l00080"></a>00080 
<a name="l00081"></a>00081     <span class="comment">// comment this out if you do not want approximation</span>
<a name="l00082"></a>00082     contours = cvApproxPoly( contours, <span class="keyword">sizeof</span>(CvContour), storage, CV_POLY_APPROX_DP, 3, 1 );
<a name="l00083"></a>00083 
<a name="l00084"></a>00084     cvNamedWindow( <span class="stringliteral">&quot;contours&quot;</span>, 1 );
<a name="l00085"></a>00085     cvCreateTrackbar( <span class="stringliteral">&quot;levels+3&quot;</span>, <span class="stringliteral">&quot;contours&quot;</span>, &amp;levels, 7, on_trackbar );
<a name="l00086"></a>00086 
<a name="l00087"></a>00087     on_trackbar(0);
<a name="l00088"></a>00088     cvWaitKey(0);
<a name="l00089"></a>00089     cvReleaseMemStorage( &amp;storage );
<a name="l00090"></a>00090     cvReleaseImage( &amp;img );
<a name="l00091"></a>00091 
<a name="l00092"></a>00092     <span class="keywordflow">return</span> 0;
<a name="l00093"></a>00093 }
<a name="l00094"></a>00094 
<a name="l00095"></a>00095 <span class="preprocessor">#ifdef _EiC</span>
<a name="l00096"></a>00096 <span class="preprocessor"></span>main(1,<span class="stringliteral">&quot;&quot;</span>);
<a name="l00097"></a>00097 <span class="preprocessor">#endif</span>
</pre></div></div>
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